BUG 1440 - json stream to normalized node stream writer

BUG 1440 - json stream to normalized node stream writer

JsonParserStream contains implementation of read method in which there
is gradually constructed structure of NodeDataWithSchema nodes.

NodeDataWithSchema is similar to SchemaNode but contains only reference to
children which really exists in JSON input and concrete values for nodes
of type leaf or leaf list.

It was necessary to firstly load JSON to NodeDataWitchSchema structure
because for some types (composite keys of list, all nodes belonging to one
augment, all nodes belonging to one choice) it isn't possible to do
sequential processing (it means to call concrete opening and closing
methods of NormalizedNodeStreamWriter interface).

JsonParserStream constructor requires schema context as input parameter.
If data behind mount point should be parsed then schema context of mount
point is required.

Change-Id: I28c1d3193792feb875ec2ceda0035ca56bfa5d42
Signed-off-by: Jozef Gloncak <jgloncak@cisco.com>
Signed-off-by: Robert Varga <rovarga@cisco.com>